It is a 'common belief' among option traders that option sellers, on average, do better than option buyers. They also believe that 'studies have shown this to be true'.
Where did this belief come from?
The book by Summa and Lubow is one of the early sources for that belief. The CBOE did a study (I believe it was in the late 1990's) that seemed to show this, and this is what prompted Summa and Lubow to put that in their book. Subsequently other authors quoted the CBOE, and Summa and Lubow to generate this accepted 'truth'.
The rationale that was invoked (not by the CBOE) for what the CBOE saw was that option buyers had a bias against them in the form of time decay of the value of the option, while option sellers had that working for them. All other things being equal, this biased trade outcomes in favor of option selling.
Is this truth really 'true'? Does it matter?
Probably some but not a lot. I believe (with no study to back it up) that given a reasonable market, a good trader will make money from either type of strategy and a bad trader will lose money from either type of strategy.
It IS true that theta acts in the option sellers favor and against the option buyer. But that is just one of many factors.
Also: Selling puts (and put spreads) is easier and simpler than some other option strategies, which is also part of the attractiveness, and I believe (with no data to support that belief) that simpler trades are more likely to be executed correctly and thus have a higher probability of success.
BTW the text I quoted is in the book descriptor on Amazon. I didn't want to plow through the book and find the direct quote, especially since I threw my copy out years ago.
